/*
 * Copyright 2024 LinQingYing. and contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * The use of this source code is governed by the Apache License 2.0,
 * which allows users to freely use, modify, and distribute the code,
 * provided they adhere to the terms of the license.
 *
 * The software is provided "as-is", and the authors are not responsible for
 * any damages or issues arising from its use.
 *
 */

package com.linqingying.cangjie.resolve.calls.smartcasts

import com.linqingying.cangjie.psi.Call
import com.linqingying.cangjie.types.CangJieType

interface ExplicitSmartCasts {
    fun type(call: Call?): CangJieType?

    val defaultType: CangJieType?

    operator fun plus(smartCast: SingleSmartCast): ExplicitSmartCasts
}
data class SingleSmartCast(val call: Call?, val type: CangJieType) : ExplicitSmartCasts {
    override fun type(call: Call?) = if (call == this.call) type else null

    override val defaultType: CangJieType get() = type

    override fun plus(smartCast: SingleSmartCast) =
        if (this == smartCast) this
        else MultipleSmartCasts(mapOf(call to type, smartCast.call to smartCast.type))
}
data class MultipleSmartCasts internal constructor(val map: Map<Call?, CangJieType>) : ExplicitSmartCasts {
    override fun type(call: Call?) = map[call]

    override val defaultType: CangJieType? get() = null

    override fun plus(smartCast: SingleSmartCast) = MultipleSmartCasts(map + mapOf(smartCast.call to smartCast.type))
}
